Clutch devices are often used to modulate torque between two shafts, such as two axle shafts in a vehicle. To engage the clutch, hydraulic pressure is applied to a piston in the device, which in turn applies pressure to the clutch to allow torque transfer between the two shafts. Because the hydraulic forces applied to the clutch are quite large, the axle housing, axle bearings, and other gear drive interfaces tend to have complex configurations to accommodate these forces. This complexity may also add to the size of the unit, which is undesirable given the trend toward smaller units with greater functionality.
There is a desire for a clutch unit with a compact structure that is also self-contained to simplify the overall design of the gear drive.